Apparatus and method for fabricating microcontainers

Abstract

An apparatus for fabricating microcontainers, the apparatus comprising: a mixer configured to contain a liquid and having a plurality of zones, the plurality of zones comprising: a reaction zone configured to contain a solution of an etching agent and a plurality of hollow glass beads for etching of the hollow glass beads therein; a sinking zone below and in fluid connection with the reaction zone and configured to allow separation of etched hollow glass beads from intact hollow glass beads therein by sinking of the etched hollow glass beads; and a collection zone below and in fluid connection with the sinking zone and configured to collect the etched hollow glass beads therein while minimizing over-etching in the collection zone.

The invention claimed is: 
     
       1. An apparatus for fabricating microcontainers, the apparatus comprising:
 a mixer configured to contain a liquid and having a plurality of zones, the plurality of zones comprising:
 a reaction zone configured to contain a solution of an etching agent and a plurality of hollow glass beads for etching of the hollow glass beads therein; 
 a sinking zone below and in fluid connection with the reaction zone and configured to allow separation of etched hollow glass beads from intact hollow glass beads therein by sinking of the etched hollow glass beads; and 
 a collection zone below and in fluid connection with the sinking zone and configured to collect the etched hollow glass beads therein while minimizing etching in the collection zone. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein the reaction zone is provided with a stirrer configured to agitate the solution and the plurality of hollow glass beads. 
     
     
       3. The apparatus of  claim 1 , further comprising a separator configured to minimize flow of solution between the sinking zone and the collection zone, the separator having at least one tubule configured to allow passage of the etched hollow glass beads therethrough from the sinking zone to the collection zone. 
     
     
       4. The apparatus of  claim 1 , further comprising an outlet provided at the collection zone for removal of the etched hollow glass beads from the collection zone. 
     
     
       5. The apparatus of  claim 1 , further comprising a number of separation meshes and barriers configured to inhibit liquid circulation in the sinking zone. 
     
     
       6. The apparatus of  claim 1 , further comprising a liquid leveller configured to allow drainage of excess solution in order to maintain a level of the solution in the mixer. 
     
     
       7. A method of fabricating microcontainers, the method comprising the steps of:
 etching a plurality of hollow glass beads in a solution of an etching agent in a reaction zone of a mixer; 
 separating etched hollow glass beads from intact hollow glass beads in a sinking zone of the mixer by allowing the etched hollow glass beads to sink in the solution; and 
 collecting the etched hollow glass beads in a collection zone of the mixer while minimizing etching in the collection zone. 
 
     
     
       8. The method of  claim 7 , further comprising agitating the solution and the plurality of hollow glass beads during the step of etching. 
     
     
       9. The method of  claim 7 , further comprising minimizing flow of solution between the sinking zone and the collecting zone via a separator provided in the mixer and passing the etched hollow glass beads through a tubule of the separator from the sinking zone to the collection zone. 
     
     
       10. The method of  claim 7 , further comprising inhibiting liquid circulation in the sinking zone during the step of separating. 
     
     
       11. The method of  claim 7 , further comprising draining excess solution in order to maintain a level of the solution in the mixer. 
     
     
       12. The method of  claim 7 , further comprising rinsing the collected etched hollow glass beads to remove residual etching agent and drying the etched hollow glass beads. 
     
     
       13. The method of  claim 7 , further comprising filling the etched hollow glass beads with a desired substance. 
     
     
       14. The method of  claim 13 , wherein the step of filling comprises vacuum evacuating the etched hollow glass beads in a vessel, adding the desired substance as a solution into the vessel containing the vacuum evacuated etched hollow glass beads to form a mixture, and filtering the mixture to obtain the microcontainers comprising etched hollow glass beads filled with the desired substance. 
     
     
       15. The method of  claim 13 , wherein the step of filling comprises adding the etched hollow glass beads into a vessel containing a solution of the desired substance, allowing the solution of the desired substance to enter the etched hollow glass beads, removing etched hollow glass beads that have been filled with the solution of the desired substance from the vessel, and evaporating a solvent of the solution of the desired substance to obtain microcontainers comprising etched hollow glass beads filled with the desired substance.